It has long been established that a number of chemical compounds typically referred to as vitamins and minerals provide significant value to maintaining an individual in a healthy state and/or treating specific medical conditions even when supplied in relatively small amounts. The human body cannot synthesize most of the vitamins and minerals that are essential to maintaining the health of the human body. Thus, vitamins and minerals must be obtained from an external source. The two most common external sources are foods and nutritional supplements. As most people do not eat foods that consistently provide the necessary daily requirements of vitamins and minerals, vitamin and mineral nutritional supplementation has become a recognized method of meeting accepted medical and health standards.
Vitamin and mineral preparations may be administered to treat specific medical conditions or as general nutritional supplements. As there are a number of vitamins and minerals needed and the daily amounts needed are relatively small, it is convenient to administer mixtures of vitamins and minerals in tablet or capsule form as a general supplement. Typical daily dosages of commercially available multivitamin and mineral supplements are one or two tablets or capsules per day. It is not unusual for such compositions to include two dozen or more nutrients in addition to the excipients needed to make the dosage form.
Accordingly, it is not surprising that undesirable chemical interactions can occur in these complex mixtures. The most common of these reactions are degradation reactions that lead to a reduced potency of the impacted nutrients and may also cause the composition to darken or develop unsightly dark spots. Oxidation reactions are exemplary of a common form of degradation reactions. The presence of water may also contribute to degradation either directly or by facilitating reactions such as oxidation reactions, for example.
Both water and fat-soluble vitamin components such as ascorbic acid (vitamin C) and alpha tocopheryl acetate (vitamin E), for example, have been found to be susceptible to moisture induced chemical degradation in multi component supplement compositions. Ascorbic acid oxidation, promoted by the interaction of ascorbic acid with polyvalent metal ions in a dietary supplement composition and facilitated in the presence of water, can cause tablet darkening and/or spotting and prolonged disintegration times that may impact availability of components for utilization in the body.
Conventionally, it has been believed that the water that contributes to degradation, is water in the environment proximate the composition (e.g. environmental water) and/or water that is loosely associated with the surface or interfacial areas of the composition. For example, the commercially available nutritional supplementation product, One-A-Day® Active, includes a storage statement which reads, “If excess moisture enters the bottle, the iron may cause spotting on the tablet.”
Accordingly, desiccants have been employed to improve stability. However, there are several problems with desiccants: First, desiccants can be physically removed from a package by the consumer negating the beneficial effect. Secondly, a desiccant may lose efficacy over time and/or have limitations in its ability to remove bound water. Thirdly, desiccants add expense to the final product.
Limiting the contents of tablets to exposure to environmental water by employing tablet coating has also been used. While this method may mask problems from a consumer's view, the polymeric film coatings used to date do not appreciably reduce spotting and/or darkening problems. Examination of aged coated tablets often reveals spotting or core darkening under the coating
Shah et al. in “A Study of the Chemical and Physical Stability of Ascorbic Acid, Folic Acid, and Thiamine Hydrochloride Tablets Formulated With Emcompress Standard®” reported that Emcompress Standard® (directly compressible dicalcium phosphate dihydrate granulation) induced ascorbic acid chemical degradation and physical degradation (with regard to disintegration times) in ascorbic acid and thiamine hydrochloride tablets. (Shah, D. H. & Aramblo, A., 1975, Drug Devel. & Ind. Pharm., 1, 459-505) The reference attributed these instabilities to the moisture associated with environmental water or water that is loosely associated with the surface or interfacial areas of the composition.
Accordingly as moisture promoted degradation reactions lead to a loss of potency and/or unappealing discoloration of multi-component nutritional supplements containing mineral ions and oxidizable vitamins, a composition and/or methods are needed to reduce moisture promoted degradation in multi-component nutritional supplements.